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From Jaanai Zhang <cloud.pos...@gmail.com>
Subject Re: Phoenix JDBC Connection Warmup
Date Sat, 02 Feb 2019 02:28:03 GMT
>
>  we experimented with issuing the same query repeatedly, and we observed a
> slow down not only on the first query

I am not sure what the reasons are, perhaps you can enable TRACE log to
find what leads to slow,  I guess that some meta information is reloaded
under highly write workload.

----------------------------------------
   Jaanai Zhang
   Best regards!



William Shen <willshen@marinsoftware.com> 于2019年2月1日周五 上午2:09写道:

> Thanks Jaanai. Do you know if that is expected only on the first query
> against a table? For us, we experimented with issuing the same query
> repeatedly, and we observed a slow down not only on the first query. Does
> it make sense to preemptively load table metadata on start up to warm up
> the system to reduce latency during the actual query time (if it is
> possible to do so)?
>
> On Wed, Jan 30, 2019 at 10:54 PM Jaanai Zhang <cloud.poster@gmail.com>
> wrote:
>
>> It is expected when firstly query tables after establishing the
>> connection. Something likes loads some meta information into local cache
>> that need take some time,  mainly including two aspects: 1. access
>> SYSTEM.CATALOG table to get schema information of the table  2. access the
>> meta table of HBase to get regions information of the table
>>
>> ----------------------------------------
>>    Jaanai Zhang
>>    Best regards!
>>
>>
>>
>> William Shen <willshen@marinsoftware.com> 于2019年1月31日周四 下午1:37写道:
>>
>>> Hi there,
>>>
>>> I have a component that makes Phoenix queries via the Phoenix JDBC
>>> Connection. I noticed that consistently, the Phoenix Client takes longer to
>>> execute a PreparedStatement and it takes longer to read through the
>>> ResultSet for a period of time (~15m) after a restart of the component. It
>>> seems like there is a warmup period for the JDBC connection. Is this to be
>>> expected?
>>>
>>> Thanks!
>>>
>>

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